Vehicle drive apparatus

Abstract

A vehicle drive apparatus independently controls drive forces for a front-right drive wheel, a front-left drive wheel, a rear-right drive wheel, and a rear-left drive wheel using a front-right electric motor, a front-left electric motor, a rear-right electric motor, and a rear-left electric motor, respectively. The drive forces for the drive wheels of a vehicle incorporating the vehicle drive apparatus are determined based on the target moments in the yaw and roll directions of the vehicle, the total drive for the drive wheels, and the drive reaction forces at the drive wheels. Thus, the performance desired by the driver can be achieved, and the drivability therefore improves accordingly.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The invention relates to a vehicle drive apparatus that can provide different drive forces at at least a pair of left and right wheels.[0003]2. Description of the Related Art[0004]When a vehicle, such as a passenger vehicle and a truck, is turning at a curve, the vehicle rolls due to inertial force acting toward the outer side of the curve. Japanese Patent Application Publication JP-A-2005-306152 describes a drive apparatus that independently drives four wheels of a vehicle and suppresses the rolling of the vehicle by controlling the drive force for each drive wheel.[0005]However, since the control performed by the drive apparatus described in this publication only suppresses the rolling of the vehicle, the yaw moment of the vehicle may become less than the level needed for the vehicle to turn appropriately or may exceed that level, and this will deteriorate the drivability of the vehicle. That is, in this case, the per...

AI Technical Summary

Benefits of technology

[0006]In view of the above, the invention has been made to provide a vehicle drive apparatus that achieves the performance desired by the driver and thereby improves the drivability of the vehicle.

[0008]As mentioned above, this vehicle drive apparatus determines the drive forces that for the left and right drive wheels based on the total drive force for the drive wheels, the drive reaction forces at the drive wheels, and at least two of the target moment required in the yaw direction of the vehicle, the target moment required in the roll direction of the vehicle, and the target moment required in the pitch direction of the vehicle. Then, the vehicle drive apparatus controls the drive forces at the respective drive wheels so as to achieve at least two of the target yaw moment, the target roll moment, and the target pitch moment. Thus, the vehicle drive apparatus according to the first aspect of the invention achieves the performance desired by the driver and thereby improves the drivability of the vehicle.

[0020]As such, the vehicle drive apparatus according to the invention achieves the performance desired by the driver and thereby improves the drivability of the vehicle.

Problems solved by technology

However, since the control performed by the drive apparatus described in this publication only suppresses the rolling of the vehicle, the yaw moment of the vehicle may become less than the level needed for the vehicle to turn appropriately or may exceed that level, and this will deteriorate the drivability of the vehicle.

That is, in this case, the performance desired by the driver can not be achieved sufficiently.

Images